[Elliotte Rusty Harold:]
> "Schema" is a generic word used in computer science.
Overloading the word "schema" is a clever way to get the RDBMS world
on board with XML. We're not interchanging documents; we're
interchanging databases by using a markup language for which the
parsers are free and standard! See, we have lexical models for our
fields, just like databases do! The marketing makes a lot of sense.
As I see it, the overloading of the word "schema" is symptomatic of a
much more general problem: the "papering over" of the differences in
the requirements that govern APIs, on the one hand, and the
requirements that govern information interchange, on the other. There
is this common wisdom out there that the structure of interchanged
information should also be, in effect, the API to that same
information. But, in fact, it's only true for a simple subset of the
kinds of information that need to be interchanged, and to which APIs
must be provided. The fact that the word "schema" is now used to mean
"model for interchange objects" as well as "model for ready-to-run
information" further hides the important distinctions between the two
realms.
I don't think anybody really benefits from this confusion, so it's
hard for me to work up any paranoia about it. It's just a phase in
the story of civilization, like feudalism. We'll get over it someday.
Probably a lot faster than feudalism.
-Steve
--
Steven R. Newcomb, Consultant
srn@coolheads.com
voice: +1 972 359 8160
fax: +1 972 359 0270
405 Flagler Court
Allen, Texas 75013-2821 USA
"We're not exactly anti-schema, but we're sure pro-DTD."
-- doctypes.org